/*
 * SPDX-License-Identifier: Apache-2.0
 *
 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 */

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
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/*
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

package org.opensearch.index.fielddata;

import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.StringField;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.SortedSetDocValues;
import org.opensearch.index.mapper.ContentPath;
import org.opensearch.index.mapper.MappedFieldType;
import org.opensearch.index.mapper.Mapper.BuilderContext;
import org.opensearch.index.mapper.TextFieldMapper;

import java.util.List;
import java.util.Random;

import static org.hamcrest.Matchers.equalTo;

public class FilterFieldDataTests extends AbstractFieldDataTestCase {
    @Override
    protected String getFieldDataType() {
        return null;
    }

    public void testFilterByFrequency() throws Exception {
        Random random = random();
        for (int i = 0; i < 1000; i++) {
            Document d = new Document();
            d.add(new StringField("id", "" + i, Field.Store.NO));
            if (i % 100 == 0) {
                d.add(new StringField("high_freq", "100", Field.Store.NO));
                d.add(new StringField("low_freq", "100", Field.Store.NO));
                d.add(new StringField("med_freq", "100", Field.Store.NO));
            }
            if (i % 10 == 0) {
                d.add(new StringField("high_freq", "10", Field.Store.NO));
                d.add(new StringField("med_freq", "10", Field.Store.NO));
            }
            if (i % 5 == 0) {
                d.add(new StringField("high_freq", "5", Field.Store.NO));
            }
            writer.addDocument(d);
        }
        writer.forceMerge(1, true);
        List<LeafReaderContext> contexts = refreshReader();
        final BuilderContext builderCtx = new BuilderContext(indexService.getIndexSettings().getSettings(), new ContentPath(1));

        {
            indexService.clearCaches(false, true);
            MappedFieldType ft = new TextFieldMapper.Builder("high_freq", createDefaultIndexAnalyzers()).fielddata(true)
                .fielddataFrequencyFilter(0, random.nextBoolean() ? 100 : 0.5d, 0)
                .build(builderCtx)
                .fieldType();
            IndexOrdinalsFieldData fieldData = shardContext.getForField(ft);
            for (LeafReaderContext context : contexts) {
                LeafOrdinalsFieldData loadDirect = fieldData.loadDirect(context);
                SortedSetDocValues bytesValues = loadDirect.getOrdinalsValues();
                assertThat(2L, equalTo(bytesValues.getValueCount()));
                assertThat(bytesValues.lookupOrd(0).utf8ToString(), equalTo("10"));
                assertThat(bytesValues.lookupOrd(1).utf8ToString(), equalTo("100"));
            }
        }
        {
            indexService.clearCaches(false, true);
            MappedFieldType ft = new TextFieldMapper.Builder("high_freq", createDefaultIndexAnalyzers()).fielddata(true)
                .fielddataFrequencyFilter(random.nextBoolean() ? 101 : 101d / 200.0d, 201, 100)
                .build(builderCtx)
                .fieldType();
            IndexOrdinalsFieldData fieldData = shardContext.getForField(ft);
            for (LeafReaderContext context : contexts) {
                LeafOrdinalsFieldData loadDirect = fieldData.loadDirect(context);
                SortedSetDocValues bytesValues = loadDirect.getOrdinalsValues();
                assertThat(1L, equalTo(bytesValues.getValueCount()));
                assertThat(bytesValues.lookupOrd(0).utf8ToString(), equalTo("5"));
            }
        }

        {
            indexService.clearCaches(false, true);// test # docs with value
            MappedFieldType ft = new TextFieldMapper.Builder("med_freq", createDefaultIndexAnalyzers()).fielddata(true)
                .fielddataFrequencyFilter(random.nextBoolean() ? 101 : 101d / 200.0d, Integer.MAX_VALUE, 101)
                .build(builderCtx)
                .fieldType();
            IndexOrdinalsFieldData fieldData = shardContext.getForField(ft);
            for (LeafReaderContext context : contexts) {
                LeafOrdinalsFieldData loadDirect = fieldData.loadDirect(context);
                SortedSetDocValues bytesValues = loadDirect.getOrdinalsValues();
                assertThat(2L, equalTo(bytesValues.getValueCount()));
                assertThat(bytesValues.lookupOrd(0).utf8ToString(), equalTo("10"));
                assertThat(bytesValues.lookupOrd(1).utf8ToString(), equalTo("100"));
            }
        }

        {
            indexService.clearCaches(false, true);
            MappedFieldType ft = new TextFieldMapper.Builder("med_freq", createDefaultIndexAnalyzers()).fielddata(true)
                .fielddataFrequencyFilter(random.nextBoolean() ? 101 : 101d / 200.0d, Integer.MAX_VALUE, 101)
                .build(builderCtx)
                .fieldType();
            IndexOrdinalsFieldData fieldData = shardContext.getForField(ft);
            for (LeafReaderContext context : contexts) {
                LeafOrdinalsFieldData loadDirect = fieldData.loadDirect(context);
                SortedSetDocValues bytesValues = loadDirect.getOrdinalsValues();
                assertThat(2L, equalTo(bytesValues.getValueCount()));
                assertThat(bytesValues.lookupOrd(0).utf8ToString(), equalTo("10"));
                assertThat(bytesValues.lookupOrd(1).utf8ToString(), equalTo("100"));
            }
        }

    }

    @Override
    public void testEmpty() {
        assumeTrue("No need to test empty usage here", false);
    }
}
